The Tenth Amendment defined a hard limit to the federal government's powers. While the nine prior amendments protect individuals' rights, this Amendment further restricts the national government's authority to only what's granted by the Constitution, or what is within their Constitutional purview. Any powers not granted would be kept for the states or their people.
The wording of the Tenth Amendment is very particular. The emphasis on “the powers not delegated to the United States government” implies broad power, rather than limiting the states to explicit powers. At the same time, due to Constitutional clauses like the Commerce Clause and the Necessary and Proper Clauses, the federal government can reasonably expand its power when necessary and address changing situations or emerging issues. The Tenth Amendment allows for state and individual rights to expand without creating an exhaustive list of their liberties. However, this can lead to ambiguity over who has power in certain situations, especially modern ones.